Means to prevent valves from sticking



Dec. 9, 1930. c. E. SUMMERS MEANS TO PREVENT VALVES FROM STICKING FiledMarch 31. 1928 IIIIIIIIIIIII/IIIIII 15 J 1 m 5.5;; 6 5m .0 o whiPatented Dec. 9, 1930 o rrEDs ATEs PATENT OFFICE CALEB n snMMERs,orronrmc, tncmean, elssrenon T GENERAL MOTQRS con- POR-ATION, ornn'rnoirgivrrcnrean, A conronerron or DELAWARE MEA S ro PREVENT VALVESFROM STIGKING Application filed March 31,

' This'invention relates to an internal combustion engineiand moreparticularly to an exhaust valve.- 7 a "One of the defects of poppetvalves is the tendency, under certain conditions, of the exhaust valvestems to stick in their guides to such an extent that the valve springpres- "sure is insuflicient to close thevalves.

Observation indicatesthat' in a majority "It isfan object of the presentinvention to prevent the sticking of the valve stems by preventing theoilfrOm W rking up along the valve stems to alpoint where thetemperature is suiiiciently high to causedecomposigradually cooler'tolowing description, taken in connection with the accompanying drawingand appended claims.

In the drawing:

Figure 1 is aitransverse vertical section with parts broken away, takenthrough a portion of an internal combustion engine embodying myinvention.

valve stem guide shown in Figure 1.

Figure 3 is a section on the line 3-3 of Figure 2. a Figure 4 is a viewsimilar to Figure 1 but showing a modified form of my invention.

Figure 5 is a view similar to Figure 1 and showing another modificationof my invention.

Referring to the drawing, I have illustrated in Figure 1 a portion of aninternal combustion engine including an engine block 1928. Serial No.266,282.

6 and cylinder head 8. The engine block,

sleeve 22. of cases, valve sticking is due to oil which i :workswupbetween the valve. stem and its guide and at somepoint between thetopand bottom of the guide, is subjected to a temperature high enough todecompose or car bonize the oil. Thepaccum'ulationiand hardening-of thematerial thus produced causes the valve to stick. p a

Slidablevin the bearing sleeve 22 is a valve stem 24 provided on itsupper end with a valve head 26 adapted to seat on the valve seat 16.,The lower end of the stem carries-a washer, 40, and surrounding the stembetween the washer 4:0 and the web 20 isthe usual valve spring 12 forholding 'the'valve seated. VThe valve stemmay be lifted in any usual 'orsuitablemanner, as by a cam shaft 11 and "tappet 30.; l i

Just-underneath the Web '20-,the bearing.

sleeve 22 is provided with a lateral recessior chamber 456; 1' Thisrecess may be produced by drilling a'hole through the, wall of thesleeve,

as shownjin Figure 3, the boreof the recess being slightly larger thantheinternal diameter of thebearin'gsleeve sothat a circular pocket I oropen space is left about, the inner surface of the'bearing sleeve,opening out through the sideof the sleeve. l V V v This clearanceinterrupts orbreaks thecontinuity of the sliding or bearing surface entirely around theperiphery ofthevalve stem and affords an annular pocketor" recess into.

which any oil carried upward on the valve stem durlng valvemovement'entfers and is col- 'lected for return to-the' tappet. chamber.

Since the clearance space completely sur- Fig re 2 isan enlarged sideview of the rounds thelvalve Stemt'he hke'hhood of 011 being pumped to apoint of high heating is ing oil gathers upon the lower end of the stemand works upward to the region of opening 46. Since thepressurexwithinthe exhaust portl4 is constantly changing and is frequently aboveatmospheric pressure while the engine is running, there may at times bea vent the rise of oil past the opening 46 and will also cause anyexcess oil to pass out through this opening. The upper portion of thesleeve 22 may be lubricatedif desired with any heat resistantlubricant,.such as, graphite.

In Figure 4: I have illustrated a slightly.

modified form of my invention in'which a bearing sleeve 23 supported theweb is provided on its inner surface with an annular groove 50, and witha port 52 through the bearing sleeve in the lower part of the groove.

Itwill be apparent that during the lifting movement of the valve =o'flits seat there will her, a valve stem guide bushing projecting thru awall of said" chamber, and "having; a

be a tendency for the lubricating oil film carried by the va lve'stem towork up on the contacting surface' o'f the guide until the contact isbroken by the annular groove where the oil is-collecte'd and returned tothe tappet chamber. A part of this oil may sti ll cling to that part ofthe stem moved into the groove and beyond the lower guide surface, andto prevent its being deposited on the upper guide surface beyond thegroove it is desirable that the siZe of groove50, takenaxial l-y of thevalve stem, be slightlygreater than the valvelift so thatthatpartof thestem which contacts with the lower guide surface when the valve isseated may move into the groove when the valve is unsea-ted, but will atno time move far enough to contact with the upper guide surface and thusthe oil thereon will not be carried past the groove 50.

In the modificationshown igu're 5, :a

bearing sleeve '60 isfixed' in web:f20 and is.

formed with a bearingsurface which is :reduced at its lower end. Journaled invthe bearing is avalve-stem comprising an upper portion 62anda reduced lower end 54. An

opening is formed in theside-ofthe bearing sleeve at the top of thereduced portion of the bearing, it being notedthat'thereduced V end 54of the valve stem extends some dis- J tance above the opening 55, thisarrangement providing an annular chamber between the valve stemand-bearing. The embodiment V illustrated in this view is otherwise thesame as thatdescribed above.

Iclaimzon the bearing surfaces 'of' valve parts o f'an internalcombustion engine or the 'like,-in-.

cluding incombination, a valve tappet chamtransver'se opening ofadiameter greater than that of the bore of the bushing drilled thru theside thereof and located below said wall to provide a space in directcommunicationwith said tappet chamber, and a valve stem slidable in saidbushing.

'2. Means to prevent 'gummin'g of lubricant diameter than the bore, toprovide an interior annular recess in direct communication with thetappet chamber, and a reciprocatory valve stem mounted in said bushing.

-3. Means to-preventgumming of lubricant on the bearing surfaces ofvalve parts of an internal combustion engine or the like, including incombination a valve tappet chamber, a valve stem guide bushingprojecting into said chamber thru a wall thereof, and having an interiorrecessed portion, the'wall of said bushing having 'anopening therethruin that portion thereof =thatextends -into said chamber, to place therecessed portion in -.di rect communication with the valve .itappetchamber, and a valve stem reciprocably mounted insaid bushing. r i I 14. The structure 'offclaim 3'wherein the length of the recessedp'ortionis greater' than the range of reciprocation of the valve.- stem.

5. Means to prevent gummingo'f lubricant on the bearing surfaces ofvalve .partsof-an said -c'hamberthru a wall thereof, anda valvestemmember slidably mounted inlsaidguide .DIGHIbBI', the adjacentsurfaces of said members=beingspaced apart for a portion oftheirextentzto Lprovide clearance therebetween, and

the wall of said guide member .having alat- ,eral opening in thatportion projecting into the tappetichamber, leading to said clearancespace, whereby said clearance space is .in

direct communication with said chamber. V

In :testimony whereof I affix my signature.

. CALEB E. ESUMMERS,

tappet

